Capsule, method and device for brewing a beverage

ABSTRACT

A capsule for use in a brewing device is provided, comprising a body part, which defines a cavity and which has a flange, a lid which is attached to the flange and tea material enclosed within the capsule, characterized in that the shape of the flange is defined by two intersecting circular arcs when viewed from above. A brewing device which comprises a capsule holder for receiving the capsule is also provided, the capsule holder comprising a sidewall which is circular when viewed from above and which has an upper rim, a shelf on at least part of the inside of the sidewall, a filter and an openable and closable passage on the opposite side of the filter from the upper rim. A method of preparing a tea-based beverage in the brewing device using the capsule is also provided.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a capsule, a method and a device forbrewing a beverage. In particular, the invention relates to infusedtea-based beverages that are brewed in a device having an infusionchamber.

BACKGROUND TO THE INVENTION

Beverages such as tea and coffee are usually prepared in the home usingground coffee, tea bags or loose-leaf tea. However, the long brewingtime required and the mess that is produced are inconvenient. Thereforebrewing devices have been devised which provide a convenient, rapid andconsumer-friendly way of brewing such beverages. The beverage materialis typically provided in a single use capsule or other container whichis disposed of after brewing the beverage. For coffee beverages thecapsule itself typically functions as the brewing chamber. The volume ofthe capsule is normally less than that of the final beverage, so it isnecessary for the brewing water to flow through the capsule. This isachieved by having a filter in the capsule so that the brewed beveragecan be dispensed whilst the beverage material is retained, and isdisposed of together with the capsule.

This method, however, is not well-suited for brewing tea, as tea leavesrequire a larger volume in which to infuse. Therefore devices forbrewing tea have been designed which have a separate, larger infusionchamber. For example, WO 2007/042485 discloses a device for preparing aninfused beverage, having an infusion container for containing liquid. Acartridge containing tea leaves is introduced into a cavity in thedevice. The bottom part of the cartridge comprises a liquid-permeablefilter. The infusion container and the cavity communicate with eachother, so that when liquid is poured into the infusion container itflows to the cartridge. The tea leaves are thus immersed in the liquidand infusion takes place. After infusion has taken place, a passagecommunicating with the cavity is opened to let the infused liquid flowfrom the infusion container through the cavity and through the filter ofthe cartridge to the passage. The spent tea leaves are collected in thecartridge and are removed from the cavity together with the cartridge.Whilst the infusion chamber allows space for tea leaves to infuse, thismethod has a number of disadvantages. In particular the cartridge mustfirstly provide sufficient area for the filter to allow the beverage tobe dispensed in a short time once brewing has taken place, and secondlyhave sufficient volume to contain the spent tea leaves which swellduring infusion, typically to around four times their dry volume. Thusthe cartridge has to be relatively large. It also has to be sufficientlystrong to support the weight of the spent tea leaves when it is removedfrom the device. Thus a substantial amount of material (e.g. plastic) isrequired to make the capsule. Furthermore, the capsule body and filterare typically made from different materials, so the capsule cannot beeasily recycled. These are both undesirable from the point of view ofcost and also environmental impact. Hence it is an object of the presentinvention to overcome these disadvantages.

BRIEF DESCRIPTION OF THE INVENTION

The present invention solves these problems by locating the filter inthe capsule holder rather than in the capsule. The capsule holder canperform the function performed in the prior art by the capsule, namelyfiltering the brewed beverage in order to retain the spent tea leaves.This of course requires that there is a route for the brewed beverage topass from the infusion chamber to the filter in the capsule holder. Thusthe capsule cannot cover the whole of the area inside the upper rim ofthe capsule holder.

We have found that using a capsule with a flange having a specific shapeallows the capsule flange to be supported by the inner rim of thecapsule holder without requiring any supporting ribs or protrusionsinside the capsule holder, whilst allowing the brewed beverage to passfrom the infusion chamber to the filter.

Accordingly, in a first aspect, the present invention provides a capsulefor use in a beverage production machine, the capsule comprising:

-   -   a body part, which defines a cavity and which has a flange,    -   a lid which is attached to the flange, and    -   tea material enclosed within the capsule,        characterized in that the shape of the flange (when viewed from        above) is defined by two intersecting circular arcs.

For ease of cleaning, it is important that the capsule holder does nothave corners or gaps in which tea leaves can become trapped. Thereforethe capsule holder is substantially circular (when viewed from above).Using a capsule with a flange having a shape defined by two intersectingcircular arcs, wherein the circular arcs have substantially the sameradius as the capsule holder, allows the capsule flange to be supportedby a shelf on the inside of the capsule holder along the whole of oneside of the capsule. This avoids the need for supporting ribs orprotrusions inside the capsule holder, which could trap tea leaves, andhinder cleaning. Therefore, in a second aspect the invention provides abrewing device comprising

-   -   an infusion chamber with a bottom rim which defines an opening;    -   a capsule holder for receiving a capsule, the capsule holder        comprising a sidewall which is circular when viewed from above        and which has an upper rim, a shelf on at least part of the        inside of the sidewall, a filter and an openable and closable        passage on the opposite side of the filter from the upper rim;    -   means for moving the capsule holder and/or the infusion chamber        so that the upper rim of the capsule holder is connected to the        bottom rim of the infusion chamber;    -   means for introducing liquid into the capsule so that the liquid        and tea material can mix and flow into the infusion chamber so        as to brew a beverage; and    -   a valve for opening the passage in the capsule holder to allow        the beverage to flow from the infusion chamber through the        filter and out through the passage.

In a third aspect the invention provides a method of preparing atea-based beverage in a brewing device according to the second aspect ofthe invention, the method comprising the steps of:

-   -   a) inserting a capsule according to the first aspect of the        invention into the capsule holder;    -   b) connecting the upper rim of the capsule holder to the bottom        rim of the infusion chamber;    -   c) introducing liquid into the capsule and releasing the tea        material from the capsule so that the liquid and tea material        mix and flow into the infusion chamber so as to brew the        beverage;    -   d) after brewing has taken place, opening the passage in the        capsule holder to allow the beverage to flow from the infusion        chamber through the filter and out through the passage.

In a fourth aspect, the invention provides the use of capsule of thefirst aspect of the invention for preparing a beverage.

DETAILED DESCRIPTION OF THE INVENTION

As used herein the term “tea material” refers to tea plant material,herb plant material or a mixture thereof. For the avoidance of doubt,the term “tea material” does not include coffee material. The term “teaplant material” refers to leaf, bud and/or stem material from Camelliasinensis var. sinensis and/or Camellia sinensis var. assamica. The teaplant material may be substantially fermented (i.e. black tea),partially fermented (i.e. oolong tea) or substantially unfermented (i.e.green tea or white tea). It may also be a blend of one or more of theaforementioned tea plant materials. Other ingredients which are commonlyused to flavour leaf tea products may also be combined with the teaplant material (e.g. bergamot, citrus peel and the like). The term “herbplant material” refers to material which is commonly used as a precursorfor herbal infusions. Preferably the herb plant material is selectedfrom chamomile, cinnamon, elderflower, ginger, hibiscus, jasmine,lavender, lemongrass, mint, rooibos (obtained from Aspalathus linearis),rosehip, vanilla and verbena. The tea material may additionally comprisefruit pieces (e.g. apple, blackcurrant, mango, peach, pineapple,raspberry, strawberry etc).

Preferably the tea material is dried and has a moisture content of lessthan 30 wt %, more preferably less than 20 wt % and most preferably from0.1 to 10 wt %. Preferably the tea material particles have a size (i.e.longest diameter) of from about 2 to about 10 mm, preferably 3 to 7 mm.

The term “beverage” refers to a substantially aqueous drinkablecomposition which is suitable for human consumption. Preferably thebeverage comprises at least 85% water by weight of the beverage, morepreferably at least 90% and most preferably from 95 to 99.9%. Preferablythe beverage comprises from 0.04 to 3%, more preferably from 0.06 to 2%,most preferably from 0.1 to 1% by weight tea solids.

The term “brewing” refers to the addition of a liquid, particularly hotwater, to tea material, so that steeping or soaking the tea material inthe liquid releases soluble substances into the liquid (e.g. flavourand/or aroma molecules) thereby to form a beverage. Brewing may becarried out at any temperature, but preferably in the range of 80 to 95°C.

The term “infusion chamber” means a vessel in which infusion of teamaterial takes place, and which is large enough both to allow the teamaterial to move around in the liquid during infusion, and also tocontain a substantial part (i.e. at least 50%) of the volume of thefinal beverage. The term “infusion chamber” therefore does not refer tocapsules inside which brewing takes place, as is typically the case incoffee machines.

The term “capsule” refers to a rigid or semi-rigid container in whichtea material is or may be packaged, for example a capsule, cartridge,pod, or the like.

The present invention will now be described with reference to thefigures, wherein:

FIG. 1 shows a brewing device according to the invention.

FIG. 2 is a schematic diagram showing the main functional components ofthe device.

FIG. 3 shows the device of FIG. 1 with the capsule holder in its loweredposition.

FIG. 4 shows the device as in FIG. 3, now with a capsule inserted intothe capsule holder.

FIG. 5 shows (a) a side view of a capsule (b) a perspective view of acapsule without a lid and (c) with a lid.

FIG. 6 shows views of capsules from above showing the shape of theflange.

FIG. 7 shows a first embodiment of the capsule holder removed from thedevice.

FIG. 8 shows a second embodiment of the capsule holder removed from thedevice, and containing a capsule.

FIG. 9 shows the manifold of the infusion chamber with an opening memberfor opening the lid of the capsule.

FIG. 1 shows one non-limiting embodiment of a brewing device accordingto the invention. The device 1 has a casing 2 with a front side 3 and arear side 4. An infusion chamber 10 and a capsule holder 20 are locatedat the front side of the device. The infusion chamber 10 has a bottomrim 12 which defines an opening in its lower side. The infusion chambermay have an opening in its top side which is covered with a removablelid 15, or it may be constructed as a vessel without an opening in itstop side. The capsule holder 20 is designed to receive a capsule. It islocated in a support 6 and preferably has a handle 22. The capsuleholder is substantially circular when viewed from above, which providesfor easy cleaning since there are no corners in which tea leaves couldbecome trapped.

In FIG. 1, the capsule holder 20 is shown in position for brewing, i.e.so that the upper rim 23 of the capsule holder is in water-tight contactwith the bottom rim 12 of the infusion chamber 10. The infusion chamber10 is supported and held in place by a manifold (not shown). A waterreservoir, heater, and pump (not shown) are located inside the rear 4 ofthe casing. At the bottom of the front side 3 of the casing there is atray 8 on which a cup 9 is placed when the beverage is dispensed. Adispensing spout 7 is positioned beneath the capsule holder.

FIG. 2 is a schematic diagram showing the main functional components ofthe device. Water from the reservoir 50 is fed to the infusion chamber10 via a water filter 52, a water pump 54, a heater 56 and a valve 57.The heater is preferably a flow-though heater. The valve 57 controls theroute the water takes between the heater 56 and the infusion chamber 10.For example, the water may firstly be pumped to the infusion chamber 10via the capsule 30 in order to brew a beverage 60. Subsequently, thevalve 57 can re-direct the water such that it enters the brewing chamber10 via a rinse head 18 in order to rinse and/or clean the brewingchamber 10. There may also be an air pump 58 which can pump air to theinfusion chamber, for example via the capsule 30 which is located in thecapsule holder 20, or via the capsule holder itself. The spout 7, cup 9and tray 8 are located beneath the capsule holder 20.

FIG. 3 shows the device of FIG. 1 with the capsule holder 20 lowered sothat its upper rim 23 is separated from the bottom rim 12 of theinfusion chamber. The capsule holder 20 is preferably removable from thesupport 6 so that a capsule can be easily inserted, and also for ease ofcleaning. FIG. 4 shows the device with a capsule 30 inserted into thecapsule holder 20, which is in the lowered position.

FIG. 5( a) shows a side view of a capsule 30. The capsule comprises abody part 31 and a lid 32. The body part 31 defines a cavity 35 in whichthe tea material 36 is placed. The lid is attached to the body part soas to enclose the tea material 36 within the capsule. The functionalityrequired of the capsule is significantly reduced compared to knowncapsules. The brewing liquid does not need to enter through one side andexit through the other, so there is no need to puncture or otherwisemake an opening in the body part of the capsule. Thus the constructionof the capsule is greatly simplified. The body part is preferably asingle, impermeable piece, and preferably does not contain any means(for example a filter, or an openable or weakened area) for allowingliquid to enter or exit the capsule through the body part. The body partis preferably made from plastic or aluminium. It may be formed forexample by injection moulding or by thermoforming.

The cavity 35 is preferably generally circular in cross-section, whenviewed from above, as shown in FIG. 5( b). This shape is convenient fromthe point of view of manufacture and also for filling tea material intothe capsule. It also facilitates release of the tea material from thecapsule during brewing, since there are no corners or other areas wherethe tea material could become trapped. “Generally circular” does notrequire that the cavity has an exactly circular cross-section; thus forexample it could have small indents, provided that there are no narrowrecesses in which tea material could become trapped.

The body part comprises a flange 33, and the lid is attached to theflange, e.g. by heat-sealing. In order to provide sufficient area toattach the lid securely, the flange is preferably at least 3 mm wide.The flange 33 also serves to support the capsule in the capsule holderby resting on a shelf on the inside of the sidewall of the capsuleholder. Thus the flange is shaped and sized to match its intendedlocation in the capsule holder. In particular, unlike the cavity, theflange is not generally circular. The flange of the capsule is definedby two intersecting circular arcs of each having a radius of curvature(R) which is substantially the same radius as the capsule holder, i.e.half of the internal diameter (D) of the capsule holder, as shown inFIG. 6( a), so that the shape of the flange generally corresponds tothat of the shelf. By “substantially” it is meant that the radii differby less than about 10%. Nonetheless, small variations from this shapecan be accommodated whilst there is still sufficient overlap between theflange and the shelf to support the capsule. Some examples of suitableshapes are shown in FIG. 6( b). In contrast, if the capsule had acircular flange, the area of contact between the inner rim of thecapsule holder and the flange of the capsule would not be sufficient tosupport the capsule. Hence extra supports would be required inside thecapsule holder, which could trap tea leaves, and hinder cleaning.

The ratio of the longest diameter of the flange to the shortest diameterof the flange is from 1.2:1 to 1.5:1. A minimum ratio of 1.2:1 isrequired in order to give sufficient surface area for the brewedbeverage to pass by the capsule and enter the capsule holder. A maximumratio of 1.5:1 is required so that the capsule is large enough tocontain sufficient tea material, without requiring an excessively largecapsule holder.

The capsule is preferably symmetrical, in that it has 180° rotationalsymmetry about a vertical axis. Thus the capsule can be placed in thecapsule holder in either of two orientations.

In a preferred embodiment, the body part of the capsule is transparent,so that the tea material inside the capsule is visible. This isattractive to the consumer, and also has the advantage that the contentscan be inspected for quality control purposes after filling usingoptical means, rather than, for example, by weight.

There is no need for the capsule to hold the spent tea leaves, nor doesthe capsule need to form a water-tight connection with the infusionchamber. In fact, the capsule is immersed in the brewing liquid. Sincethe capsule only needs to be large enough to contain a single serving ofthe dry tea material it can be much smaller than known capsules. Thusthe internal volume of the capsule (i.e. the volume of the cavity) isfrom 10 to 24 cm³, preferably 12 to 19 cm³, most preferably from 14 to18 cm³. Moreover, the capsule only needs to be strong enough to supportdry tea material, and not wet spent tea material. Thus the body part ofthe capsule can also have relatively thin walls.

The reduced capsule size means that the amount of material (e.g.plastic) needed to make the capsule is significantly reduced. This hasenvironmental and cost advantages. Furthermore, the capsule body partcan be more easily recycled because it is made of a single material,unlike typical capsules having a filter. A small capsule also has theadvantage of taking up less space during transport and during storage,for example in a consumer's cupboard.

The cavity must not be so shallow that tea material bounces out of itduring filling. Thus the depth of the cavity is preferably at least 10mm, more preferably at least 13 mm. On the other hand, the cavity mustnot be so deep that it is difficult to remove the tea material from thecapsule at the start of brewing. Thus the depth of the cavity ispreferably at most 20 mm, more preferably at most 18 mm. It is easier toremove the tea material from a cavity with a depth in the upper part ofthis range when the volume of the cavity is also towards the upper endof its range (i.e. when the cavity is not both deep and narrow).

The cross-sectional area and diameter of the cavity are related to therequired volume and depth. Consequently, the diameter of the cavity ispreferably from 30 to 45 mm. The lid, which overlaps with or covers theflange as well as covering the cavity, is therefore preferably fromabout 45 to 60 mm in diameter, more preferably 47 to 58 mm. The lid ispreferably shaped to generally match the shape of the flange.

The lid can be a simple thin film or foil. The lid is preferably made ofa metallic foil or a laminated foil, most preferably a laminate ofaluminium foil and polyethylene. In a preferred embodiment, the shape ofthe lid is defined by two intersecting circular arcs, but with truncatedends 38, as shown in FIG. 5( c). The length of the lid between the twotruncated ends is from 47 to 58 mm, and the maximum width of the lid isfrom 45 to 50 mm.

Preferably the lid has perforations in order to facilitate opening thecapsule to inject water and release the tea material, as will bedescribed below. More preferably the lid 32 has a line of perforations34 in the form of a curve, with sections which extend backwards from theends of the curve, as shown in FIG. 5( c). This configuration produces awell-defined opening when the lid is pushed against a blunt openingmember (described below), which allows the tea leaves to be releasedfrom the capsule. Most preferably there are two sets of perforations inthe lid, arranged symmetrically, as shown in FIG. 5( c), so that inwhichever of the two possible orientations the capsule is inserted, oneset of perforations is always located beneath the opening member. Thecut:tie ratio of the perforations should be such that they do not bursttoo easily, for example during transport, but nonetheless open withoutrequiring too great a force. For example, for an aluminiumfoil/polyethylene laminate lid, a cut:tie ratio of around 1:2 issuitable.

Typically the capsules are provided to the consumer in air-tightsecondary packaging, for example as multipacks containing a plurality ofcapsules (e.g. ten). The multipacks may contain packages of a singletype, or a mixture of packages containing different types of tea (e.g.green tea, black tea, herbal tea). Having a perforated lid has a furtheradvantage in that some of the tea aroma is released from the teamaterial inside the capsule into the space inside the secondarypackaging. Thus the consumer obtains the aroma of tea on opening thesecondary pack.

FIG. 7 shows one embodiment of a capsule holder removed from the devicein cross-section. The capsule holder 20 has a sidewall 24 with an upperrim 23 and a base 26. For ease of cleaning, it is important that thecapsule holder does not have corners or gaps in which tea leaves canbecome trapped. Therefore the sidewall 24 is circular when viewed fromabove.

A filter 25 is located inside the capsule holder. A shelf 28 on theinside of the sidewall 24 just below the upper rim 23 supports theflange 33 of the capsule 30 above the filter 25. Beneath the filter 25is a passage 29 through which the beverage flows during dispensing andwhich is closed by a drain valve 21 during brewing.

The filter preferably consists of a fine mesh made, for example, ofstainless steel, nylon, polyester or PTFE. The mesh size must besufficiently small to catch small pieces of tea material but largeenough to ensure that draining is not too slow. Preferably, the meshsize is from 100 to 500 microns, more preferably 150 to 300 microns.Preferably the filter (when in its normal position in the device) isinclined to the horizontal at an angle of from 5 to 45°, preferably from10 to 30°, such as about 20°. Having the filter at an angle to thehorizontal has two advantages: firstly it presents a larger surfacearea, and hence increases the speed of draining. Secondly tea materialcollects at the bottom of the sloped filter while leaving the upper partclear of tea material so that the beverage drains freely through it.

FIG. 8 shows perspective views of a second embodiment of the capsuleholder 20 which consists of two separable parts, a receptacle 70 and astrainer 72. FIG. 8( a) shows the capsule holder when assembled with acapsule 30 in place, and FIG. 8( b) shows the capsule, strainer andreceptacle separated.

The receptacle 70 has a sidewall 24 and a base 26. Again, the sidewallis circular when viewed from above. Located in the base 26 is a passage29 through which the beverage flows during dispensing and which isclosed by a drain valve (not shown) during brewing. The receptacle 70has a handle 22.

The strainer 72 has a base 73, a rim 74 and a handle 75. A shelf 78 onthe inside of the sidewall 24 just below the rim 74 supports the flange33 of capsule 30 above the base. The shelf extends around part of thesidewall, corresponding to one side of the flange 33. The sidewall iscircular (when viewed from above), so the shelf has the form of an arcof a circle. It is not essential that the shelf is continuous, providedthat it is capable of supporting the flange of the capsule. Thus forexample, the shelf could have small gaps. The width of the shelfpreferably matches the width of the flange, i.e. it is at least 3 mmwide. The part 80 of the flange 33 which rests on the shelf 78 isindicated in FIG. 8( a). Small members 71 on the shelf ensure that thecapsule is located in the correct position and in one of the twopossible correct orientations.

At least part of the base 73 of the strainer is made up of a filter 25.In the preferred embodiment shown in FIG. 8( b), the part of the base 73which is located underneath the capsule is solid whilst the rest of thebase consists of the filter. The filter preferably consists of a finemesh made, for example, of stainless steel, nylon, polyester or PTFE.The mesh size must be sufficiently small to catch small pieces of teamaterial but large enough to ensure that draining is not too slow.Preferably, the mesh size is from 100 to 500 microns, more preferably150 to 300 microns.

As shown in FIG. 8( a), in use the strainer 72 rests on the receptacleand is supported by the sidewall 24. The rim 74 of the strainer formsthe upper rim 23 of the capsule holder 20. The strainer covers the wholeof the top of the receptacle 70, so that liquid cannot pass between therim 74 of the strainer and the sidewall 24 of the receptacle, and hencecan only enter the receptacle 70 by passing through the filter. Thefilter prevents spent tea leaves from entering the receptacle 70.Preferably the rim 74 is made from an elastomeric material. Thereby itis in effect a gasket which forms seals both between the receptacle andthe strainer, and also between the capsule holder and the infusionchamber.

This embodiment has the advantage that the strainer and receptacle canbe easily separated for cleaning. Moreover, in order to empty out spenttea leaves from the capsule holder, it is only necessary to remove thestrainer and tip the spent leaves out from it.

Preferably the handle 75 of the strainer is larger than and overlaps thehandle 22 of the receptacle. When the strainer is located in thereceptacle, the handle 75 of the strainer sits on top of handle 22 ofthe receptacle, as shown in FIG. 8( a). This allows the receptacle andstrainer to be picked up together, by gripping them from above andbelow. Nonetheless, the strainer can be easily removed from thereceptacle by gripping the edges of its handle 75 where it extendsbeyond the handle 22 of the receptacle.

The handle 75 of the strainer may optionally have a projection 77 on itslower side, which rests in a corresponding hollow 79 in the top side ofthe handle 22 of the receptacle. This helps to locate the strainercorrectly with respect to the receptacle. The strainer may optionallyhave a lip (not shown) on its rim, for example located opposite thehandle, which rests in a corresponding notch in the top of the sidewallof the receptacle. This helps to locate the strainer correctly withrespect to the receptacle, and also to support it.

In use, the device functions as follows. With the capsule holder in itslowered position, the user removes the capsule holder from the support,or in the second embodiment of the capsule holder shown in FIG. 8, theuser may just remove the strainer from the receptacle. A capsulecontaining tea material is placed into the capsule holder where it restson, and is supported by, the shelf on the inside of the sidewall of thecapsule holder, just below the upper rim.

The capsule holder is then replaced on the support. Next the user raisesthe support, for example by pressing a button on the device whichactivates an actuator. The capsule holder travels vertically upwardsuntil it connects with the infusion chamber, and forms a water-tightseal. In an alternative embodiment, the infusion chamber could move downtowards the capsule holder.

In the context of the present invention, ‘connecting the upper rim ofthe capsule holder to the bottom rim of the infusion chamber’ and ‘theupper rim is connected to the bottom rim of the infusion chamber’ shouldbe understood to mean that upper rim of the capsule holder and thebottom rim of the infusion chamber form a water-tight contact, so thatthe capsule holder and infusion chamber form a vessel in which thebrewing liquid can be held while brewing takes place. The capsule holderand infusion chamber may be connected by means of an intermediate membersuch as a gasket (for example a ring made of rubber or other compliantmaterial located on the upper rim of the capsule holder and/or thebottom rim of the infusion chamber) in order to provide a good seal. Theinfusion chamber and the capsule holder form a space for brewing whenconnected. Preferably the volume of the space for brewing is at least75%, more preferably at least 90% of the volume of the final beverage.

The device may have means for recognizing a capsule and/or readinginformation from a code associated with the capsule or the capsuleholder. Different codes may be associated with different types of tea(e.g. green tea, black tea, herbal tea etc.). This allows the capsule tobe recognized by the device, so that the device can automatically setthe parameters for the brewing operation, such as the brewing time,water temperature etc. It also allows the device to be programmed sothat it only operates if the correct type of capsule is present. Thus avalid code signifies that an expected type of capsule is present, and aninvalid code signifies an unexpected type of capsule, a capsule that hasalready been used or that no capsule is present. The recognition systemcan be of any suitable type, such as mechanical interlocking between thecapsule and the capsule holder; optical recognition (e.g. by means ofcolour, fluorescence or bar code), electrical, magnetic, radio-frequencyidentification (RFID) chip etc.

Optionally, the device may also have means for allowing the user toadjust the parameters of the brewing operation, such as the brewingtime, the receptacle size etc. The means may suitably consist of buttonsor other inputs on the device, together with a control system.

The lid of the capsule needs to be opened or removed in order to releasethe tea material. Preferably, the lid is opened automatically by thedevice after the capsule has been inserted into the capsule holder, e.g.as the upper rim of the capsule holder is connected to the bottom rim ofthe infusion chamber. Preferably, two openings are made in the lid, oneto introduce liquid into the capsule and the other to release liquid andtea material into the infusion chamber. However, because the capsuledoes not have a filter, there is no need to puncture or otherwise makean opening in the base of the capsule.

In a preferred embodiment, shown in FIG. 9, the lid is opened by pushingit against one or more static opening members when the capsule holdertravels upwards to connect with the bottom rim of the infusion chamber.The lid 32 is pushed against a static opening member 40 located on theinfusion chamber manifold 16. The function of the member is to create anopening in the lid in order to release liquid and tea material. This canbe achieved by a member with a sharp edge which cuts or punctures thelid. Alternatively, the lid may have pre-formed weaknesses, such asperforations 34 which reduce the force required to open it. In thiscase, the member 40 can be blunt, for example a wire. Preferably themember is angled or has a sloped part 41 so that as it moves into thecapsule, the flap formed by opening the lid is pushed away from theopening and held out of the way whilst the tea material is released fromthe capsule.

In the preferred embodiment shown in FIG. 9, a second opening forintroducing liquid into the capsule is made by pushing the lid against astatic needle 42 consisting of a tube with a pointed end. The needle 42pierces the lid. Water is then pumped from the reservoir to the heater,which is preferably a flow-though heater. The resulting hot water (andoptionally steam) is then pumped to the capsule and enters it throughthe needle. The influx of hot water pushes the tea material out from thecapsule through the opening made by the opening member 40 and into theinfusion chamber 10.

The heater and pump are controlled so that the target brew temperature(which is typically in the range 80° C. to 95° C.) is achieved in theinfusion chamber. Typically the water flow rate is in the range of 200to 400 ml/min, and the volume of water is 150 to 300 ml, depending onthe desired size of the beverage.

Preferably the infusion chamber 10 is made of transparent material suchas glass, or transparent plastic, so that the user can see the motion ofthe tea material (such as tea leaves) whilst the beverage is brewing.Most preferably, the infusion chamber is made of Tritan™ copolyesterbecause this material is transparent and has been found to have goodresistance to staining. Air may be pumped into the capsule holder 20(e.g. via the static needle) or directly into the infusion chamber 10 tocreate bubbles in the water and thereby agitate the tea material. Thisnot only enhances the visual appearance, but also aids infusion andhelps to prevent the tea material from sticking to the sides of theinfusion chamber. Moreover, the introduction of air releases aroma whichcan optionally be vented via a tube, which for example, has an outletnear to the dispensing spout or near the top of the infusion chamber,thereby providing the user with the aroma of tea during brewing. Thebrewing time, which typically ranges from 10 to 120 seconds, ispreferably set by user input and/or information read from the capsule.

Once brewing has taken place for the required time, the drain valve 21located in the base of the capsule holder 20 is opened, allowing thebeverage to drain from the infusion chamber. Preferably the opening ofthe drain valve is controlled automatically by the machine. The beverageflows from the infusion chamber through the filter 25 located in thecapsule holder below the capsule, through the passage 29, and finallyinto a cup 9 which the user has already placed onto the tray 8. Teamaterial is prevented from entering the cup 9 by the filter 25.

Optionally, there may be a dispensing spout 7 positioned beneath thecapsule holder as shown in FIG. 1, so that the beverage is dispensedthrough the drain valve and out through the spout. Thus, instead ofbeing dispensed vertically downwards into the receptacle, the beveragefollows an arc, similar to that of tea poured from the spout of a teapot. This enhances the “theatre” provided by the machine for the user,and also emphasizes the “tea-ness” of the beverage, as distinct fromcoffee making machines.

After the beverage has been dispensed, the spent tea material may berinsed from the wall of the brew chamber with further hot water.Preferably the rinsing water is introduced through rotating rinse jets18 located near the top of the infusion chamber. Better rinsing isachieved by rotating rinse jets than static ones. In a preferredembodiment, rinsing takes place immediately after the beverage has beendispensed, and the rinse water is also dispensed into the receptacle andbecomes part of the beverage. This removes the need for separatedisposal of the rinse water. In this case, the rinse water providesaround 15-30% of the total volume of the beverage, e.g. the volume ofrinse water used is around 50 ml.

Finally, after the beverage has been dispensed, the capsule holder islowered, preferably automatically, or alternatively by the user, forexample by activating a button. The user then removes the capsule holderfrom the support, using the handle 22, or in the second embodiment ofthe capsule holder shown in FIG. 8, the user may just remove thestrainer from the receptacle. The used capsule and spent tea leaves arethen disposed of, and the capsule holder can be rinsed.

Since the capsule holder is removable from the brewing device, it iseasy to clean. The capsule holder is then returned to the support, readyfor the next use.

The device can be cleaned, for example by running a rinse cycle with notea material or by running a cycle with a cleaning material, for examplesodium percarbonate. The cleaning material can be provided in a capsule,or alternatively as a tablet which is simply placed in the capsuleholder.

The various features of the embodiments of the present inventionreferred to in individual sections above apply, as appropriate, to othersections mutatis mutandis. Consequently features specified in onesection may be combined with features specified in other sections asappropriate. Various modifications of the described modes for carryingout the invention which are apparent to those skilled in the relevantfields are intended to be within the scope of the following claims.

1. A capsule (30) for use in a brewing device, the capsule comprising: abody part (31), which defines a cavity (35) and which has a flange (33),a lid (32) which is attached to the flange (33), and tea material (36)enclosed within the capsule, characterized in that the shape of theflange is defined by two intersecting circular arcs.
 2. A capsuleaccording to claim 1 wherein the ratio of the longest diameter of theflange to the shortest diameter of the flange is from 1.2:1 to 1.5:1. 3.A capsule according to claim 1 or claim 2 wherein the cavity has agenerally circular cross-section.
 4. A capsule according to any ofclaims 1 to 3 wherein the volume of the cavity is from 10 to 24 cm³,preferably 12 to 19 cm³.
 5. A capsule according to of claims 1 to 4wherein the depth of the cavity is from 10 to 20 mm and the diameter ofthe cavity is from 30 to 45 mm.
 6. A capsule according to any of claims1 to 5 wherein the shape of the lid substantially matches the shape ofthe flange.
 7. A capsule according to any of claims 1 to 6 wherein thelid is defined by two intersecting circular arcs with truncated ends(38).
 8. A capsule according to claim 7 wherein the length of the lidbetween the two truncated ends is from 47 to 58 mm, and the maximumwidth of the lid is from 45 to 50 mm.
 9. A capsule according to any ofclaims 1 to 8 wherein the lid comprises metallic foil, preferably alaminate of aluminium foil and polyethylene.
 10. A brewing device (1)comprising an infusion chamber (10) with a bottom rim (12) which definesan opening; a capsule holder (20) for receiving a capsule (30), thecapsule holder comprising a sidewall (24) which is circular when viewedfrom above and which has an upper rim (23), a shelf (28) on at leastpart of the inside of the sidewall, a filter (25) and an openable andclosable passage (29) on the opposite side of the filter from the upperrim; means for moving the capsule holder and/or the infusion chamber sothat the upper rim (23) of the capsule holder is connected to the bottomrim (24) of the infusion chamber; means (42) for introducing liquid intothe capsule so that the liquid and tea material can mix and flow intothe infusion chamber so as to brew a beverage; and a valve (21) foropening the passage in the capsule holder to allow the beverage to flowfrom the infusion chamber through the filter and out through thepassage.
 11. A device according to claim 10 wherein there are members(71) on the shelf which abut the flange of the capsule and therebylocate the capsule in the intended position and/or an intendedorientation.
 12. A device according to claim 10 or 11 wherein thecapsule holder comprises a separable receptacle (70) and a strainer (72)in which the filter (25) is situated.
 13. A capsule according to any ofclaims 1 to 9 wherein the circular arcs have substantially the sameradius as the capsule holder.
 14. A method of preparing a tea-basedbeverage in a brewing device according to any of claims 10 to 12, themethod comprising the steps of: a) inserting a capsule (30) according toany of claims 1 to 9 into the capsule holder (20); b) connecting theupper rim (23) of the capsule holder (20) to the bottom rim (12) of theinfusion chamber (10); c) introducing liquid into the capsule (30) andreleasing the tea material from the capsule so that the liquid and teamaterial mix and flow into the infusion chamber (10) so as to brew thebeverage; d) after brewing has taken place, opening the passage (29) inthe capsule holder (20) to allow the beverage to flow from the infusionchamber (10) through the filter (25) and out through the passage. 15.Use of a capsule according to any of claims 1 to 9 for preparing abeverage.
 16. A multipack containing a plurality of capsules accordingto any of claims 1 to 9.